Drill jig



May 22, 1945- F. -wRlGH-r DRILL JIG Fi1ed June 26, 1943 W RL/u 0R 603 am62 Jaw ,Jima r .A 0 z f memA 5. www5 4J. l v

ATTORNEYS.

Patented May22, 1945 l UNITED `"s-'nrrE-s i? DRILL .11G Frank`WrighhrEast Orange, N. J., assigner to Breeze' Corporations, Inc.,Newark,` N. J., a corporation of New Jersey Application .ninev 26, 194s,serial No. .492,657

' i (ci. vr-czy 2 Claims. This invention relates to 4appliances andtools Vfor holding work parts, while being 'subjected to mechanicaloperations, such as milling, grinding,

and more particularly drilling, such devices being commonly Acalledjigs.

Thefunction of'such, apparatus is to locate a work part therein withreference to drill guiding bushings set permanently in thejig, the wor-kbeing part adjustably. positioned. by openingsin it, previously nnishedsurfaces, etc., and then securely, but releasably, clamped Withincronthe Jlg.- .I

In case the article to be drilled is supplied with one or more openings,such as are molded, cast or otherwise formed, and which may taper,present irregularities, -or vary otherwise from being truly cylindrical,it is obvious they will not closely nt fixed circular locating studs inthe jig.

If the work part openings loosely lt such studs, the centers of theholes to be drilled may vary in distance and location from that requiredinadmissibly.

It is an object of the invention to provide a jig, or similar appliance,for holding an article while being machined, as by drilling, withuniformly expansible locating means, enterable in one or more openingsin the article, whereby the openings are positioned precisely concentricwith .the locating means, irrespective of inaccuracies in the openings.

A further feature is in the provision of a novel locating means forarticles having substantially circular openings, whereby the article isautomatically adjusted to aline the axes of the open ings with the axesof the locating means, prior to clamping, and without possibility ofdamage to the article.

Another purpose is to produce a work-holding jig in which the locatingmeans take up the thrust of the cutting tool, eliminates vibration andconsequently chatter.

These and analogous objects are attained by the novel and practicalconstruction, combination and arrangement of parts hereinafter fullydescribed and shown in the annexed drawing, forming a material part ofthis disclosure, and in which:

Figure 1 is a. perspective View of an embodiment of the inventionillustrating its application.

Figure 2 is a sectional view taken through the longitudinal center ofthe device.

' Figure 3 is a transverse sectional view looking on line 3-3 of Figure2.

Figure 4 is a similar sectional View looking on line 4-4 of Figure 2.

Figure 51is a.y ftoprplan. detail view: of the jig body, looking on lineA5- 5 of Figure 2.,

Figure 6 is a detail expanded view of one locating studs, collarl andsleeve.-

As shownin the-drawing, `a work part., generf allyindicated bythecharacter S,y having at upper and lower faces and parallel flat sides,convexly curved at the endshas a narrow curved-v extensionfl',vinvvhiclrisl a ,circular hole U. y

A similar hole V is formedthrough thejbody S, these holes4 beingpartially yconnected. by a slot W; rearward-,of lille` holes isa counterbored opening X, while further out is a, small opening Y.

This article is molded from some of the many phenolic substances andtherefore the several holes are slightly tapering, yet it is Arequiredto drill a passage Z, at a right angle to the holes and exactly midwaytherebetween.

It is to be understood that the foregoing details are given only as anexample of any article in which one or more holes exist and which are tobe machined with respect to their axes; these holes may be polygonal,rough interiorly, tapered, or be otherwise than ytruly cylindrical, andof different sizes, therefore incapable of ttng straight locating postsor studs with a requisite degree of accuracy necessary to exactness inma.-

of the chine operations on the article.

The jig shown may be of an exceedingly simple character, consisting of achannel shaped structure composed of a base plate I5, having raisedparallel sides I6 and preferably provided with feet I1.

Set rigidly inthe base I5 are two locating studs I8 and I9, the stud I8being axially drilled and tapped to produce a screw thread 20, in itsupper portion, while the stud I9 has an extending threaded stern 2l,these studs being very considerably less in diameter than the holes U'and V,

A knurled thumb screw 26 having an enlarged body 21 is fitted to engagethe threads of the lstud I8, and a knurled thumb nut 28 havinga flange29 is fitted to the stem 2|.

One or more hardenedsteel bushings 30 are accurately positioned in thesides I6 of the jig,

Afl-"ENT A- )FF1LCE 7 y L exactly midway the axes of the studs I8 andi9,

Q the thrustof a'cutting tool istakenfon one or l more resilient;supports,v f

and at such height or distance from the base as may be required.

While the'expanside element 22 has beenA described as rubber, it isobvious that suitable lequivalent vexpansible means may be substituted.

It is found in practice that neoprene, which is resistant to the eiectof oil and grease used to lubricate the cutting tool, is satisfactory.

The collar 22 is preferably composed of homogeneous'material in order toinsure uniform expansion thereof. i,

In operation, the article to be drilled is looselyf` l' disposed on theoor of the base 45, the studs,

with their expansible collars and sleevesV freely entering the holesvinthe article.

Thereafter the screw 26 and nut 28 are applied, Y

causing the sleeves to exert pressure on' the collars, whereby they areuniformly expanded latferally, shifting the article if required, bycentering the holes exactly' on the axes ofthe studs andthereafterclamping the` Aarticle in its adjusted position. if'

ject to such changes and modications as may support to engage in theopenings, a` radially expansible collar on each post, a sleeve slidableFrom the foregoing Vit Will be apparent that the 3 work part is, inameasure,- vcushion supported,

which principle visvcapable ofuse for other purposes than drilling; thatthe jig'is subject to many forms-,for workY part holding, and in whichAlthough the foregoing is YVdescriptive of a simple-.embodiment of@hell/invention, it is: subon each post in contact with said collar,yandy i `.means whereby the collar is dilated to fill each 'work-partopening, said means being also adapted "gto cofincidently clamp thework-part on said support. Y y

2. A drill jig 'adapted 'to position a work part having at least twoapertures extending therethrough in spaced parallel relation, saidpartto be drilled at a right angle at a predetermined distance from thecenters of the'apertur'es, said jig 'y beingcomposed of a base havingraised side walls,

studs iixed in said base to extend through the `apertures free fromcontact therewith, an ex- .pansible sleeve on each stud, means todilatesaid sleeves to fill the apertures,said means also being operative toclamp the work part when positioried by said sleeves,`and drillguidingvmeans xed insaid-side wallsac'curately distanced-.from

the axes of said studs. v

- FRANK WRIGHT.

